r interpolation for limited number of NA

i have a dataframe df with a column containing values (meter reading). Some values are sporadically missing (NA).

df excerpt:

row   time      meter_reading
1     03:10:00  26400
2     03:15:00  NA
3     03:20:00  27200
4     03:25:00  28000
5     03:30:00  NA
6     03:35:00  NA
7     03:40:00  30000

What I'm trying to do:

If there is only one consecutive NA, I want to interpolate (e.g. na.interpolation for row 2). But if there's two or more consecutive NA, I don't want R to interpolate and leave the values as NA. (e.g. row 5 and 6).

What I tried so far is loop (for...) with an if-condition. My approach:

for(i in 1:(nrow(df))) {
  if(!is.na(df$meter_reading[i]) & is.na(df$meter_reading[i-1]) & !is.na(df$meter_reading[i-2])) {
    na.interpolation(df$meter_reading) 
    }
}

Giving me :

Error in if (!is.na(df$meter_reading[i]) & is.na(df$meter_reading[i -  : 
  argument is of length zero

Any ideas how to do it? Am I completely wrong here?

Thanks!